regarding list box control?

Hi Sree,


Try this...


using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Data.OleDb;
namespace WindowsFormsApplication1
{
   
    public partial class Form1 : Form
    {
        OleDbDataAdapter oledbda;
        string ConnectionString = System.Configuration.ConfigurationSettings.AppSettings["dsn"];
        string str;
        OleDbCommand com;

        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            listBox1.Items.Add("Raj");
            listBox1.Items.Add("Raju");
            listBox1.Items.Add("Rahul");
            listBox1.Items.Add("Harry");
            listBox1.Items.Add("Ben");
            listBox1.Items.Add("Ian");

        }

        private void btn_insert_Click(object sender, EventArgs e)
        {
            OleDbConnection con = new OleDbConnection(ConnectionString);
            con.Open();
            str = "select count(*)from student where sname='" + listBox1.SelectedItem + "'";
            com = new OleDbCommand(str, con);
            int count = Convert.ToInt32(com.ExecuteScalar());
            con.Close();
            if (count > 0)
            {
                lblMessage.Text = "Sorry! you can't take this student name";
            }
            else
            {
                lblMessage.Text = "You can take this student name";
                con.Open();
                str = "insert into student(sname) values('" + listBox1.SelectedItem + "')";
                com = new OleDbCommand(str, con);
                com.ExecuteNonQuery();
                con.Close();

            }
        }
       
    }
}




Thanks
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